Electrospray Emitter Arrays for High-throughput Ionization of Liquids


  • Mass-efficient nanosatellite electric propulsion
  • Multiplexed focused ion beam imaging
  • High-throughput nano-manufacturing

Problem Addressed

Efficient high-throughput generation of ions using electrospray ionization is of great importance for many technological applications, but the current and mass flow rates produced by a single electrospray emitter are relatively small to satisfy most practical embodiments. To this end, new configurations and methods of use for electrospray arrays are needed to meet the throughput demands that applications require.


The batch-microfabricated electrospray emitters allow for low-voltage, high-throughput generation of ions from ionic liquids. The invention has a hierarchical structure which brings together optimized structures with characteristic lengths spanning five orders of magnitude: mesoscale deflection springs for precision assembly of the extractor electrode die to the emitter array die, microscale emitter tips for field enhancement and low-voltage electrospray emission, and a nanostructured conformal CNT wicking structure that controls the flow rate fed to each emitter to attain high emitter current while maintaining good array emission uniformity.


  • Four-fold increase in emitter density than the state of the art (2000 emitters in 1 cm2)
  • 10-fold increase in per-emitter current in both polarities than the state d the art ( 10 uA per emitter)